Lubricant



render them suitable for use under high oper- 40 ating pressures. These compounded oils function (mi-CHI satisfactorily under conditions which would cause Pb failure of an unblended mineral oil, if used alone. HPCH/ It is believed that the successful use of such compounded oils depends upon the adsorption and cycmmmmemylemlead .45 reaction or union of certain components of these Gin-0H, oils with the metal surfaces whereby a film of me- ILCH: tallic compound, such as, for example,'iron sulflde or chloride is formed. It appears that such a film or plating has a low coeflicient of friction yc tet e e met ylp osph ne and that satisfactory operation of heavily loaded r (Harem bearings or gears depends upon the formation and I maintenance of such a film, and not upon the re- K T taining of -a film of oil between the bearing surri Patented J ne 6,1939 I 2 150 915.

UNITED STATES PATENT OFFICE LUBRICANT William Schreiber, Philadelphia, re, assignor to The Atlantic Refining. Company, Philadelphia, Pa., a corporation of Pennsylvania No' Drawing. Application October 24, 1938, Serial .No. 107,367

3 Claims. (Cl. 87-9) The present invention relates to the art of extreme pressure lubricant serves primarily to lubrication, and more particularly to the lubricaremove frictional heat, to wash away any solid tion of surfaces engaging under extreme presparticles which may result from wear, and to sure, as for example, the rubbing surfaces of hyprevent oxidation of the engaging surfaces. poid gears, free wheeling transmissions, speed re- I have discovered that organic heterocyclic 5 ducers and the like. a I compounds, and more particularly heterocyclic The general tendency in the design of modern compounds containing one or more elements machinery has been toward a higher ratio beother than carbon in the ring, when admixed tween power and dead weight". This is e'swith hydrocarbon oils, are of special utility in the pecially true in the automotive industry, and in field of extreme pressure lubrication. Among. recent years certain types of gears and other the compounds which may be employed in acmechanisms have been developed with the Opercordance with my invention are the heterocyclic ating pressures on the working surfaces 50 high compounds containing at least one element from that ordinary mineral oil lubricants will not the group P, S, Se, Te, Si, As, Sb, Sn, Bi, Cd, provide suflicient lubrication for satisfactory op- Cu, Ni, Fe, Zn, Pb, Hg and Al introduced directly eration. into ring or nucleus. In general, the compounds Heretofore it has been thought that lubricamay be represented by the following formulae: tion consists in maintaining a film of oil between (011K), (CHE the rubbing surfaces, thereby preventing them I l:

from coming into contact with one another and thus preventing wear. That this condition exists ((LHlt (01111 I in well lubricated bearings is well known, but this (CHE) (OER conception of lubrication does not apply to highly loaded gears. In well lubricated bearings the B X R' loads rarely exceed 2000 lbs. per. sq. in. projected (011m)" \(CHRM area and the rubbing speeds are generally high enough to maintain a film of oil which separates wherein R, R2 R3 ay be alkyl, aryl. althe rubbing surfaces. In automobile gears, the karyl or heterocyclic oup ydro en or halopressures between gear teeth reach very high X and K1 are of the group 5, Se, Te, values and even the most viscous oils' or greases r A5, C11, Ni, 8 cannot be retained between the surfaces of the d d n and m are at least The r ups teeth in a sufficiently thick film to prevent metal R2 may e represented y m thyl-. to metal contact, particularly when operating ethyl" D DY and likehomologues; p e y n temperatures of 210 F. or higher are commonly p yln anthracyland e ke; encountered. I furyl-, pyridyl-, thienyland the like; hydro- It has been" known that compounded lubricants and halogen $11011 as C o e, bromine or such as, for example, mineral oils containing fatty fi oils, fatty acids, metallic soaps, sulfur or The heterocyclic compounds of this invention bined chlorine, possess lubricating qualities which y be u e exemplified y h f l w ng:

faces. The hydrocarbon oil constituent of an cyclmpentamethylenephenylimosphim,

, C H:- C H:

(.iyclo-pentamethylene mercury Hg- 0 H:

S \C Hg-C HI 1,4 thloxane C H- C H! 8 B CHr-CHK 1,4 dithloxane GHrCHa O Be om-om 1,4 selenoxa ne CH -CH: P-{hHs CH CH:

Ethyl 1,4-phosphoxane CHr-C H2 AS-CQH CHr-C H1 Cyclo-pehtamethyleue phenyl arsine CHrCHs-CHz-CHI Hg \Hg CRrCHrCHr-CHz Octamethylene mercury-1,6 O/C H: CHCl\ \CH!CH2/ 2-chloro, 1,4 thioxane OBHECHR-CH! Zn H:CH2

B-phenyl cyclo-tetremethylene zinc In preparing my lubricant, I add to a suitable mineral oil one or a mixture of two or more of the heterocyclic compounds in quantity sufficient to improve the lubricating value of the oil to the desired extent, depending upon the operating conditions under which the lubricant is to be used. I have found that the quantity of the compound required, in general, does not exceed substantially by weight of my composition. Quantities as small as 3%, or even 1% or 'less, have been found to improve lubricating oils to a satisfactory extent. In certain instances, 0.1% to 0.2% by weight of the heterocyclic compound was sufficient to improve the lubricating oil to the desired extent. In preparing my lubricant, I may obtain a homogeneous solution or stable suspension of the compound in mineral oil by agitating the mixture at normal or elevated temperatures, or I may dissolve the compound in a suitable solvent and add the resulting solution to the oil, thereafter removing the solvent by vaporization.

The mechanism by which the heterocyclic compounds in lubricating oils function to improve the load-bearing ability and other properties thereof is not entirely understood. It appears, however, that the functioning is dependent upon the adsorption of the compounds'upon the metal surfaces of the bearings or other lubricated parts, and the reaction or chemical combination of such compounds with the metal under the influence of localized high temperature and pressure to form a coating or plating having a low coefficient of friction which is resistant to seizure under high operating pressures.

A typical example of my improved lubricant and the method of preparing same is as follows:

0.2 mol of 5c dichloroethyl ether, 0.2 mol of phosphenyl chloride CsHsPClz and 1.15 mols in metallic sodium were refluxed, in ether solution, on a steam bath for about 22 hours. To this reaction mixture was added another 0.8 mol of metallic sodium and the refluxing was contin ued for an additional 14 hours. The reaction mixture was then cooled and washed twice with 5% aqueous KOH solution and twice with water. The washed mixture was then dried, and the ether diluent and unreacted chloro ether were removed from the product by distillation. Approximately 1% by weight of the reaction product, i. e., the phenyl derivative of 1,4 phosphoxane, was added to a hydrocarbon lubricating oil having a Saybolt universal viscosity of 376 sec-' onds at 100 F. and an A. P. I. gravity of 29.1, and a homogeneous solution was obtained. Upon testing the lubricant in an Almen extreme pressure lubricant testing machine at 200 R. P. M., a pressure of 22,000 lbs./sq. in. projected bearing area was sustained before seizure of the bearing occurred; whereas the unblended lubricating oil failed at a pressure of 4,000 lbs/sq. in. projected-bearing area. The same reaction product, when added to the same lubricating oil in the amount of 0.25% by weight, sustained a pressure of 17,000 lbs/sq. in. projected bearing area.

It will be seen from the above example, that the addition of a heterocyclic compound to a hydrocarbon oil improves the lubricating value of such an oil to a marked degree, and imparts to the oil certain properties which render it suitable for use in the lubrication of surfaces engaging under extreme pressure. Under certain conditions, for example in the lubrication of transmissions or gear drives where elevated temperatures are not normally encountered, it has been found thatthe halogenated, and particularly the chlorinated heterocyclic compounds are more eflicient than the unchlorinated compounds in their ability to improve the load-bearing capacity of the lubricants.

Furthermore,- I have found that heterocyclic compounds of the present invention having as substituents long hydrocarbon chains or substituted hydrocarbon chains, are capable of not only improving the load-bearing capacity of hydrocarbon oils but also effect a lowering of the coefiicient of friction, or improve the oiliness of the lubricant. The heterocyclic compounds containing long chain alkyl radicals such as cetyl, lauryl, dodecyl and. oleyl, and the substitution products thereof, are representative examples of this type of materials.

While I have described 'my invention with ref erence to the lubrication of gears and bearings operating under heavy loads, I do not intend to' limit myself thereto, but. contemplate the .use of my lubricant in operations such as the cutting and boring of metals, in whichconditions of extreme pressure and temperature are normally encountered, and also in the lubrication of mechanisms operating under moderate pressures, as

. Iorexample, the crankcase bearings and cylinder walls of internal combustion engines. Furthermore, my compounded oil may be utilized as a base in the preparation of thickened oils,,i. e'., greases, by the addition thereto of soaps or other conventional thickening agents, in order to obtain lubricants of desiredviscosity. My compounded oil may also be blended with fatty oils, fatty acids, synthetic esters and the like, or the heterocyclic compounds, per se, may be admixed with fatty oils, for the lubrication of mechanisms in which the presence of a fatty oil is desirable.

What I claim is:

1. A lubricant comprising hydrocarbon oil and a small amount, sumcient to impart extreme pressure'properties to the oil, of a cyclo-polymethylene compound containing a phosphorus atom and an oxygen atom within the ring 2. A lubricant comprising hydrocarbon oil and a small amount, sufiicient to impart extreme pressure properties to the oil, of an aryl substituted pho'sphoxane.

3. A lubricant comprising hydrocarbon oil and a small amount, sufficient to impart extreme pressure properties to the oil, of phenyl 1,4- phosphoxane.

WILLIAM SCI-IREIBER. 

